diff --git a/firewall/firewall-add b/firewall/firewall-add
index aa7c240..ed253cd 100755
--- a/firewall/firewall-add
+++ b/firewall/firewall-add
@@ -248,9 +248,10 @@ fi
 
 prerouting() {
 	if [ "$(set |grep -w SOURCE_IFACE)" != "" ]; then 
+		if [ "$TARGET_IP" != "" ] && [ "$TARGET_PORT" != "" ] ; then
 		debug "$IPTABLES -I PREROUTING -i $SOURCE_IFACE -p $PROTOCOL --dport $SOURCE_PORT -m comment --comment $COMMENT -j DNAT --to $TARGET_IP:$TARGET_PORT"
 		$IPTABLES -w -I PREROUTING -i $SOURCE_IFACE -p $PROTOCOL --dport $SOURCE_PORT -m comment --comment "$COMMENT" -j DNAT --to $TARGET_IP:$TARGET_PORT
-
+		fi
 	elif [ "$SOURCE_IP" != "" ]; then
 		if [ "$SOURCE_PORT" != "" ]; then
 			if [ "$TARGET_IP" != "" ]; then